Fireproof is a very useful perk that negates fire and slowly take damage from lava. This can help in situations where a meteor is impacting the land and burning it, or if the land under you is destroyed and fall in lava. You're also immune to Fireball and Spicy Turkey.
Perk Tips Edit
If you have the "Second Perk Slot". Fireproof goes extremely well with Double Jump as it's one of the best combos to use on intensity mode.